What is incomplete dominance?
a third phenotype that blends two parentals
What is codominance?
progeny displays both phenotypes together
What is an example of codominance in humans?
Blood
What is variable pentrance?
a proportion of individuals of the same genotype that will either express the determined phenotype or not at all
What is variable expressivity?
degree at which the genotype is expressed differs
What is pleiotropy?
one gene controlling two or more apparently unconnected phenotypes
What is polygenic inheiritance?
many genes affecting one phenotype
What does non-complementation suggest?
allelism-one locus involved-mutations of the same gene
What does complementation suggest?
non-allelic mutants-more than one gene is responsible for the phenotype
What is an auxotroph?
mutants that need supplementation
What is additive gene action?
2 genes influencing one phenotype-making 4 phenotypes
What is the ratio for an additive gene action?
9:3:3:1
What is complementary gene action?
homozygous recessive for either pairs of alleles leads to recessive phenotype (e.x. ccP_ or C_pp)
What is the ratio for complementary gene action?
9:7
What is redundancy?
dominant alleles of both genes overpower one anothers recessive (aka one dominant allele in entire genotype means dominant)
What is the redundancy ratio?
15:1
What is epistasis?
phenotype of a gene is masked by alleles of another
What is recessive epistasis?
when the recessive allele of one gene masks the effect of either the dom or rec allele of the second gene
What is dominant epistasis?
when the dominant allele of one gene masks the effect of either dom/rec allele of the second gene
What is the modified ratio of a recessive epistatic interaction?
9:3:4
What is the modified ratio of dominant epistasis?
12:3:1
